The Orient Express was the name of a long-distance passenger train service created in 1883 by Compagnie Internationale des Wagons-Lits (CIWL).

The route and rolling stock of the Orient Express changed many times. Several routes in the past concurrently used the Orient Express name, or slight variants thereof. Although the original Orient Express was simply a normal international railway service, the name has become synonymous with intrigue and luxury travel. The two city names most prominently associated with the Orient Express are Paris and Constantinople (Istanbul), the original endpoints of the timetabled service.